JSON error: java.lang.String cannot be converted to JSONObject

I'm developing an android app and I'm trying to use Volley Library. The problem that I can't solve is about the JSON. I checked my php file, the result and the Java code but I'm still getting the same error.

The interesting part is that VolleyLog doesn't show an error message but, Log, does.

E/Volley﹕ [1] 2.onErrorResponse: VOLLEY_ERROR

and

E/LOG﹕ Error: org.json.JSONException: Value You of type java.lang.String cannot be converted to JSONObject